Don't get me wrong, I heard good things about Play, but isn't it Scala? Vaadin I know only from a customer of mine who are using it for server-rendered charting apps and I guess it works well in that capacity. And Spring MVC in 2017? Come on.

My point being that these frameworks are chosen because the options are limited to what's available on the JVM, trading last-gen Java know-how against younger (and sexier) know-how.

It's also a miracle to me why JavaScript isn't more popular with Java developers, of all people, when in fact Java has two mature JavaScript engines, and JavaScript certainly is interesting from a bridge/migration perspective. Years ago Oracle and RedHat had even partial Node.js ports, but it never went very far.

Play is for Scala and Java too. Vaadin does much more than charts--although its wrapping of highcharts is pretty nice--and is quite pleasant if you'd rather write Java than HTML and its close relatives.

I guess from the Java perspective, Javascript does not look too sexy, as it is a small but dangerous / unhelpful language with an uncompetitive-to-Java library ecosystem. TypeScript is great however.

> uncompetitive-to-Java library ecosystem

React, Webpack, CSS compilers and pretty much all other modern frontend (compile-time) asset tools are running on Node.js and install from npmjs.com. Node.js is also perfect for a shallow web-facing container developed along with the front-end as a complement to Java-based (mini/SOA/whatever)-services. So I think it's quite useful to make Node.js workloads run under the JVM.

When we talk about rich libraries we mean actual libraries for generating PDFs, reading barcodes, report generation, talking with all kinds of enterprise databases, GPU programming, parallel distributed algorithms, embedded development...

Not yet another packaging tool or fait-divers like pad left.

And the majority of them written in pure Java, not C++ wrapped in a JavaScript API.

> When we talk about rich libraries we mean actual libraries for generating PDFs

I was specifically talking about web libraries/tools, though. Nobody is saying Java backend development must be abandoned in general.

How do you generate a PDF on such a cool JavaScript front end application?

Hint, you don't. Just hope that the browser does a good job with print to PDF, or run a server side pile of shell scripts, using LaTeX and Postscript, instead of a plain simple library.

And this is just one example from many, where JavaScript/Web sucks on the front-end.

Also Android is front-end development.